Modern Smartphone devices are equipped with location-based features. These devices use signals from GPS satellites to identify a location, determine a direction of motion, and other navigation functions. Typically, in locations where the GPS satellite signals are weak (e.g., indoors) GPS may not function well or at all. To provide indoor navigation, some devices may use other information such as wireless network signals, Bluetooth signals, compass data, and accelerometer data as well as existing floor plans and pre-generated databases or indices of measurement.